Methods of manufacturing semiconductor devices having capacitors

1. A method of removing polymer generated in a semiconductor manufacturing process, which includes sequentially depositing a lower metal layer, an insulating layer and an upper layer on a semiconductor substrate; forming a photoresist pattern on the upper metal layer; and etching the upper metal layer and the insulating layer by using the photoresist pattern as a mask, the polymer being generated during the etching step, the method comprising:

(a) removing the photoresist pattern by using O 2 /N 2 plasma;

(b) removing the polymer existing on the lower metal layer by using H 2 O/CF 4 plasma; and

(c) using a plasma from a gas consisting essentially of O 2 , removing residues of the photoresist pattern remaining after (b).

2. A method as defined by claim 1 , wherein (a) is carried out for about 50 seconds.

3. A method as defined by claim 1 , wherein a flow rate of a CF 4 gas in (b) is in a range from 5% to 15% of that of a H 2 O gas.

4. A method as defined by claim 1 , wherein powers used in the (a), (b) and (c) are substantially same.

5. A method as defined by claim 1 , wherein a process time of (c) is in a range from 40% to 60% of that of (a).

6. A method as defined by claim 1 , wherein a process time of (b) is in a range from 30% to 50% of that of (a).

7. A method of manufacturing a semiconductor device having a capacitor, the method comprising:

(a) sequentially depositing a lower metal layer, an insulating layer and an upper metal layer on a semiconductor substrate;

(b) forming a first photoresist pattern on the upper metal layer;

(c) forming an upper electrode film and a capacitor insulating film by etching the upper metal layer and the insulating layer by using the first photoresist pattern as a mask;

(d) removing the first photoresist pattern by using O 2 /N 2 plasma;

(e) removing polymer existing on the lower metal layer by using H 2 O/CF 4 plasma, then removing remaining residues of the first photoresist pattern using a plasma from a gas consisting essentially of O 2 ;

(f) forming a second photoresist pattern for completely encapsulating the upper electrode film and the capacitor insulating film;

(g) forming a lower electrode film by etching the lower metal layer by using the second photoresist pattern as a mask; and

(h) removing the second photoresist pattern to provide the capacitor including the lower electrode film, the capacitor insulating film and the upper electrode film.

8. A method of removing polymer from a lower metal layer having an insulating layer and an upper metal layer thereon, the lower metal layer on a semiconductor substrate, the upper metal layer having a first photoresist pattern thereon, the method comprising steps of:

(a) removing the first photoresist pattern by ashing with a first plasma from a first gas mixture consisting essentially of O 2 and N 2 ;

(b) removing the polymer on the lower metal layer by ashing with a second plasma from a second gas mixture consisting essentially of H 2 O and CF 4 ; and

(c) removing remaining residues of the first photoresist pattern with a third plasma from a gas consisting essentially of O 2 .

9. A method as defined by claim 8 , wherein step (a) is carried out for about 50 seconds.

10. A method as defined by claim 8 , wherein step (b) comprises flowing CF 4 gas at a rate of from 5% to 15% of that of H 2 O gas.

11. A method as defined by claim 8 , wherein steps (a), (b) and (c) each use substantially the same power.

12. A method as defined by claim 8 , wherein a process time of step (c) is from 40% to 60% of that of step (a).

13. A method as defined by claim 8 , wherein a process time of step (b) is from 30% to 50% of that of step (a).

14. The method of claim 8 , further comprising, prior to step (a), steps of sequentially depositing the lower metal layer, the insulating layer and the upper metal layer on the semiconductor substrate; forming the first photoresist pattern on the upper metal layer; and forming an upper electrode by etching the upper metal layer using the first photoresist pattern as a mask.

15. The method of claim 14 , further comprising, after forming the upper electrode and prior to step (a), forming a capacitor insulating film by etching the insulating layer using the first photoresist pattern as a mask.

16. The method of claim 15 , further comprising, after step (b), steps of forming a second photoresist pattern completely encapsulating the upper electrode and the capacitor insulating film; forming a lower electrode by etching the lower metal layer using the second photoresist pattern as a mask; and removing the second photoresist pattern to provide a capacitor including the lower electrode film, the capacitor insulating film and the upper electrode film.

17. A method as defined by claim 1 , wherein the O 2 /N 2 plasma is formed from a gas mixture consisting essentially of O 2 and N 2 .

18. A method as defined by claim 17 , wherein removing the photoresist pattern is performed before removing the polymer existing on the lower metal layer.

19. A method as defined by claim 8 , wherein the O 2 /N 2 plasma is formed from a gas mixture consisting essentially of O 2 and N 2 .

20. A method as defined by claim 19 , wherein removing the photoresist pattern is performed before removing the polymer existing on the lower metal layer.

21. A method as defined by claim 8 , wherein removing the first photoresist pattern is performed before removing the polymer on the lower metal layer.